Time delay relay



Feb. 24, 1942. p, w, swENsoN 2,274,013

TIME DELAY RELAY Filed June 28, 1940 IIHI'IMP INVENTOR R W SWENSON A TTORNE V resistance, itfloiidimbtmtrtherevwiil :hfi'xCOB-fidi? er'ablemargin between thevmzximaimacimuiticur- 2 iit withsmaximuml-mltadeuanti.minimsm fly.

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extends in series through both windings and rear ends which extend eelyoug holes in when closed, the armature is attracted only to the ends orthe arms of the bracket 8 by means such an extent as to close one pairoi. the conof which the armature is pivoted to the bracket. tactsprings, this initial first step moyement'of I. For a full disclomre oithe U-shaped hinge 6 may, for example, have between the cross-reach ofthe armature and the pole face 3 of the core.

Supported on each end of the heel-piece 2 is a spring pile-up, eachpile-up comprising a plurality of contact springs of which some areactive or operating springs, such as I! and II, and of which others arepassive springs such as ll and i6, and a pair of winding terminal lugsI1 and l8. Each pile-up is clamped to the heel-piece 2 by screws I!which extend through aligned holes in the clamping plate 2|, in theterminal lugs i1 and It, in the bracket I, in the heelpiece 2, in thespacer II, in the springs II to Ii, inclusive, and in the strips ofinsulation 82 to 28, inclusive, into threaded holes in the clampingplate 30. The insulating strips 22 to II serve to insulate the terminallugs l1 and II and the springs I3 to is, inclusive, from each other.from the clamping plates II and ll and from the heelpiece 2. The screwsll are also suitably insulated in the well-known manner from theterminal lugs H and I8 and from the contact springs II to M, inclusive,by insulated bushing! which surround their threaded shanks.

For operating the springsof each pile-up, an operating stud ill ofinsulating material is associated with each pile-up and is engagedagainst the armature 9. The stud II is ring-staked to the operatingspring i3, extends freely through the passive spring I with its outerend separated from the operating spring Ii by a stud gap, whereby whenthe armature is attracted, the

springs l3 and I5 are successively operated into engagement with springsll and I. The springs is are tensioned to normally bias the end of thearmature against the backstop nut ll. It will be noted that the contactgap between springs l3 and I4 is adjusted to be narrower than thecontact gaps between the other pairs of springs of the relay, so thatupon the attraction of the armature toward the core, the springs II andI make their contacts first.

The relay may be provided with a sleeve 3! surrounding its core betweenthe core and the coil 4 asdisclosedinFig.2inlieuoftheslug'l. It is to befurther understood that the spring pileups of the relay may compriseanydesired number and combination of contact spring! within theoperating capacity of the relay.

The operation of the relay will now be considered in connection with thecircuit diagram of Fig. 2 in which the have been disclosed as separatearmatures, each operating aseparate spring pile-up. when the operatingcircuit of the relay is initially closed, it extends from ground throughany desired circuit closer, thence serially through the non-inductivewinding 8 and'the operating winding I to grounded battery. Thenon-inductive winding a resistance or I50 ohms and the operating windingmay have a resistance of 1000 ohms. With the non-mductive winding}connected in series with the operating winding ,theoperatingwindingsehupaflux in the magnetic circuit of the which is mlytwo legs of the armature l mfiicienttooperatethearmaturetomch sitionastoclosethecontact springs ll butnottomove spring ll intoengagement s ringI! ortooperatetheother contact Thebuiiding upofthisiiuxisdelayedduetotheprovision of the short-circuited sleeve 81 or sluginglbecomesincreasedwherebythefluxflowingthroughthemagnetlccircuitoftherelayis increasedtoavaluerequisitetofullyowlte the armature.Thebuildingupotthisincreasedflux value is, however, delayed due to theprovision o! the short-circuiting sleeve 32 or the slug I. When afterthis second interval. the armature becomes fully operated, the remainingsprings of the spring pile-ups, such as springs I0 and II, become engaed.

From the foregoing description it will b2 seen that the applicant has,simply by the provision of an additional relay winding, ofarmature-operated contacts for removing such winding from the normalseries connection with the operating winding of the rein-mend of ashort-circuiting sleeve or slug, devised a relay which operates itsarmature in two slow-to-operate steps thereby securing a longeroperating time. It will be obvioustothoseskilledintheartthattherelay maybe further simplified by placing the non-inductive winding 6 as aseparate resistance external to the relay, but normally connected inseries with the operating winding I.

What is claimed is: V

1. In combination, a core, an armature cooperating therewith, aplurality of contact springs operable by said armature, ashort-circuited sleeve and an operating winding on said core, aresistance, a source of current, an operating circult including saidsource of current, said operating winding and said resistance in series,whereby upon the closure of said circuit saidwindingproducesaiiowoffluxinsaidcoreretarded in its build up by saidsleeve to operate saidarmatureonlysumcientlytocloseonepair of saidcontact springs, and a shunt around saidresistanuclcsedbysaidonepairofsprings whereby said winding produces afurther flow of flux in said core, retarded in its buildupbysaid sleeve,to fully operate said armature to operate the remaining contact springs.

operable 2. In combination, a core, an armature cooperating therewith, aplurality of contact springs by said armature, a short-circuited sleevean operating winding and a non-inductive winding on said core.-a sourceof current, an opmature tooperate theremainhm springs.

mm. W. swsusou.

